1. Field of the Invention
The present invention relates to a method of producing metal hydroxides in an easy-to-separate powder form, as well as to various applications of this method.
2. Discussion of Background Information
Metal hydroxides of the general formula Me (OH).sub.n are usually prepared by the action of an alkaline solution on soluble metal salts, to precipitate hydroxides which have a finely divided and often a gelatinous appearence.
The gelatinous appearance obtained does not facilitate washing or the hydroxide and separating it by filtration from the starting solution and from the washing waters. It is therefore difficult to obtain the hydroxide in a powder form with an acceptable purity.
In some other cases, in particular when the hydroxides are soluble in an alkali medium, for example the hydroxides of amphoteric metals, they may in theory be obtained as precipitates by neutralizing a strong base with an acid. In many practical applications, the metals which are dissolved in strong base media are not recovered, but the solutions containing them are purely and simply discharged, with the consequent risks of pollution and toxicity.